Photographic material and process comprising a coupler capable of forming a wash-out dye (Q/Q)

ABSTRACT

A photographic element comprises a support bearing at least one photographic silver halide emulsion layer and at least one coupler (A) having a water solubilizing group wherein coupler (A) forms a compound that is washed out of the photographic element during photographic processing and forms a coupling-off group represented by the formula: 
     
         --X--Rel.sup.2 --T.sup.2 --INH 
    
     wherein; 
     X is selected from oxygen, nitrogen or sulfur; 
     X--Rel 2  contains a photographic ballast and is a releasing group for releasing T 2  --INH from X--Rel 2  by elimination electron transfer reaction during photographic processing without substantial delay of releasing; 
     T 2  is a timing group that releases INH by elimination electron transfer reaction with timing delay during photographic processing; 
     INH is a development inhibitor group. 
     The photographic coupler (A) enables formation of easily removable dyes in photographic elements and processes that provide images having improved acutance, stability and interimage effects.

This invention relates to a new photographic coupler that is capable offorming a wash-out dye in a photographic material upon photographicprocessing to form an image having improved acutance, stability, andinterimage effects, and a photographic material and process using such acoupler.

Various ways are recognized in the photographic art for release of aphotographically useful group (PUG), such as a color developmentinhibitor, from a compound, such as a coupler, in a photographicmaterial and process. For example, U.S. Pat. Nos. 4,248,962, and4,861,701 describe compounds that release photographically useful groupsby means of an intramolecular nucleophilic displacement reaction inphotographic materials. Other examples of means for release ofphotographically useful groups are described in, for example, U.S. Pat.Nos. 4,409,323 and 4,861,701. These compounds, particularly couplers,capable of releasing a photographically useful group provide a degree ofcontrol over timing and rate of release as well as rate of diffusion anddistance of diffusion of the photographically useful group.

The part of the compound that remains in the photographic material afterrelease of the photographically useful group and dye that is formed inthe material from reaction with oxidized color developer often providesundesired properties in the photographic material during or afterphotographic processing. For example the dye formed from a coupler uponrelease of a photographically useful group often adversely affects thedesired image. One answer to this has been to provide a coupler that hasa water solubilizing group on the parent coupler to enable the dyeformed from the coupler to be washed-out of the photographic elementupon photographic processing. Such couplers are described, for example,in U.S. Pat. No. 4,482,629.

A need has existed to provide a coupler, in a photographic material andprocess that enables formation of an image having improved acutancewhile enabling removal by wash-out of the dye formed from the couplerduring photographic processing. Moreover, such needs have existed withthe added parameter that such a compound must not require significantlymodifying the development inhibitor group in a way that would adverselyeffect the ultimate end use of the groups.

The present inventions solve these problems by means of a photographicelement comprising a support bearing at least one photographic silverhalide emulsion layer and at least one coupler (A) having a watersolubilizing group wherein coupler (A) is capable of forming a compoundthat is washed out of the photographic element during photographicprocessing and has a coupling-off group represented by the generalformula:

    --X--REL--T--INH

wherein;

X is selected from oxygen, nitrogen or sulfur;

X--Rel is a releasing group for releasing T--INH from X--Rel by eitherintramolecular displacement reaction or electron transfer reactionduring photographic processing without substantial delay of releasing;

T is a timing group that releases INH by either elimination electrontransfer reaction or intramolecular displacement reaction with timingdelay during photographic processing; and

INH is a development inhibitor group.

The X--Rel--T--INH is released from the coupler moiety upon oxidativecoupling of the coupler. During photographic processing, the reaction ofcoupler (A) with oxidized color developing agent cleaves the bondbetween the coupling-off group and the coupler moiety. Then the bondbetween X--Rel (RELEASING GROUP) and the T (TIMING GROUP) is cleavedwithout substantial delay of release. The bond between the T and the INHis then cleaved with timing delay. The cleavage of the bond between theINH and the T can be enabled by for example, an elimination such as theone described in U.S. Pat. Nos. 4,409,323 and 4,959,299, or for example,by an intramolecular displacement reaction, such as one described in,U.S. Pat. No. 4,248,962. Choosing substituent parts of the X--Rel and Tto requirements of the given INH allows control over the timing and rateof release of the INH.

The inventions are described in classes in more specific details asfollows:

CLASS 1

In the first invention a photographic element, as noted, is providedcomprising a support bearing at least one photographic silver halideemulsion layer and at least one coupler (A) having a water solubilizinggroup wherein coupler (A) is capable of forming a compound that iswashed out of the photographic element during photographic processing.Coupler (A) has a coupling-off group represented by the formula:

    --X--REL.sup.1 --T.sup.1 --INH

wherein;

X is selected from oxygen, nitrogen or sulfur

X--Rel¹ is a releasing group for releasing T¹ --INH from X--Rel¹ byintramolecular displacement reaction during photographic processingwithout substantial delay of releasing;

T¹ is a timing group that releases INH by elimination electron transferreaction with timing delay during photographic processing; and

INH is a development inhibitor group.

The X--Rel¹ as described is any X--Rel¹ releasing group which releasesT¹ --INH from X--Rel¹ by an intramolecular displacement reaction duringphotographic processing without substantial delay of releasing. TheX--Rel¹ as described is not a timing group that substantially delaysrelease of T¹ --INH. The X--Rel¹ can serve as a carrier for aphotographic ballast group for the coupler prior to exposure andphotographic processing.

A typical X--Rel¹ group is represented by the formula: ##STR1## wherein;R¹ and R² is selected from hydrogen, substituted or unsubstituted alkyl,and substituted or unsubstituted aryl;

R³ is unsubstituted or substituted alkyl or substituted or unsubstitutedaryl;

R⁴ is hydrogen or a substituent which does not substantially delayrelease of T¹ --INH;

Z¹ represents the atoms necessary to complete a 5 or 6 member aryl orheterocyclic group; and

n is 0, 1 or 2.

A substituent which does not substantially delay release of T¹ --INH andthe substituted or unsubstituted alkyl and substituted or unsubstitutedaryl, may be selected from nitro, hydrogen, amino, substituted amino,carboxylic acid, sulfonic acid, methoxy, chloro, bromo, ester groupssuch as --CO₂ CH₃, keto groups such as --COCH₃, or --NHCOCH₃, --CONHCH₃,--NHSO₂ CH₃, or --SO₂ NHCH₃.

At least one of R¹, R², R³ and R⁴ can be a photographic ballast group.

The T¹ as described is any timing group that releases INH by anelimination electron transfer reaction that enables a time delay betweenthe oxidative coupling of the coupler (A) and the release of INH. The T¹differs from the X--Rel¹ in that T¹ enables time delay whereas X--Rel¹does not enable substantial time delay.

A typical T¹ is represented by the formula: ##STR2## wherein; Z²represents the atoms necessary to complete a 5 or 6 member arylene orheterocyclic group;

R⁵ and R⁶ is selected from hydrogen, substituted or unsubstituted alkylor substituted or unsubstituted aryl;

R⁷ is hydrogen or a substituent which does not substantially delayrelease of T¹ --INH from X--Rel¹.

A substituent which does not substantially delay release of T¹ --INH,the substituted or unsubstituted alkyl and substituted or unsubstitutedaryl, may be selected from nitro, hydrogen, amino, substituted amino,carboxylic acid, sulfonic acid, methoxy, chloro, bromo, ester groupssuch as --CO₂ CH₃, keto groups such as --COCH₃, or --NHCOCH₃, --CONHCH₃,--NHSO₂ CH₃, or --SO₂ NHCH₃.

The X--Rel¹ is preferably a group as described in U.S. Pat. No.4,248,962 that enables release of T¹ --INH from X--Rel¹ by means ofintramolecular T¹ is preferably a group as described in U.S. Pat. Nos.4,409,323 and 4,959,299 that enables release of INH from T¹ by means ofan electron transfer, preferably by an ethylenic conjugated chain.

A typical coupler (A) of Class 1 of the Invention is a naphtholiccoupler represented by the formula: ##STR3## wherein; R⁹ is selectedfrom a photographic ballast and a substituent which does notsubstantially delay release of T¹ --INH;

R¹⁰ is selected from substituted and unsubstituted alkyl containing 1 to3 carbon atoms and a photographic ballast; and

R¹¹ is nitro. Other groups which may be considered in place of nitro arehydrogen, amino, carboxylic acid, sulfonic acid, methoxy, chloro, bromo,ester groups such as --CO₂ CH₃, keto groups such as --COCH₃, or--NHCOCH₃, --CONHCH₃, --NHSO₂ CH₃, --SO₂ NHCH₃, or R¹¹, in combinationwith the timing group T¹, can constitute a substituted or unsubstitutedpyridyl moiety.

R¹² is hydrogen, CH₃, methoxyphenyl, hydroxyethoxyphenyl, carboxyphenyl,--CH₂ CO₂ CH₃, --CH₂ CH₂ COOH or --CH₂ OCH₂ CH₂ COOH; and

INH is a heterocyclic development inhibitor group.

An especially preferred naphtholic coupler is represented by thestructures I-1 through I-12, of table 1.

CLASS 2

In the second invention a photographic element as noted, is providedcomprising a support bearing at least one photographic silver halideemulsion layer and at least one coupler (A) having a water solubilizinggroup wherein coupler (A) is capable of forming a compound that iswashed out of the photographic element during photographic processing.Coupler (A) has a coupling-off group represented by the formula:

    --X--REL.sup.2 --T.sup.2 --INH

wherein;

X is selected from oxygen, nitrogen or sulfur

X--Rel² contains a photographic ballast and is a releasing group forreleasing T² --INH from X--Rel² by elimination electron transferreaction during photographic processing without substantial delay ofreleasing;

T² is a timing group that releases INH by elimination electron transferreaction with timing delay during photographic processing;

INH is a development inhibitor group.

The X--Rel² as described is any X--Rel² releasing group which releasesT² --INH from X--Rel² by an elimination electron transfer reactionduring photographic processing without substantial delay of releasing.The X--Rel² as described is not a timing group that delays release of T²--INH. The X--Rel² can serve as a carrier for a photographic ballastgroup for the coupler prior to exposure and photographic processing.

A typical X--Rel² group is represented by the formula: ##STR4## wherein;R¹³ is hydrogen or a substituent which does not substantially delayrelease of T² --INH;

R¹⁴ and R¹⁵ is selected from hydrogen, substituted or unsubstitutedalkyl, and substituted or unsubstituted aryl;

Z¹ represents the atoms necessary to complete a 5 or 6 member aryl orheterocyclic group.

At least one of R¹³, R¹⁴ and R¹⁵ can be a photographic ballast group.

A substituent which does not substantially delay release of T² --INH andthe substituted or unsubstituted alkyl and substituted or unsubstitutedaryl, may be selected from nitro, hydrogen, amino, substituted amino,carboxylic acid, sulfonic acid, methoxy, chloro, bromo, ester groupssuch as --CO₂ CH₃, keto groups such as --COCH₃, or --NHCOCH₃, --CONHCH₃,--NHSO₂ CH₃, or --SO₂ NHCH₃.

The T² as described is any timing group that releases INH by anelimination electron transfer reaction that enables a time delay betweenthe oxidative coupling of the coupler (A) and the release of INH. The T²differs from the X--Rel² in that T² enables time delay whereas X--Rel²does not enable substantial time delay.

A typical T² is represented by the formula: ##STR5## wherein: R¹⁶ ishydrogen or a substituent which does not substantially delay release ofT² --INH from X--Rel² ; R¹⁶, R¹⁷, and R¹⁸ are chosen to provide aminimum time delay of at least 5 seconds.

R¹⁷ and R¹⁸ are selected from hydrogen, substituted or unsubstitutedalkyl or substituted or unsubstituted aryl and are chosen not tosubstantially delay release of T² --INH from X--Rel² ;

Z² represents the atoms necessary to complete a 5 or 6 member arylene orheterocyclic group.

A substituent which does not substantially delay release of T² --INH,and the substituted or unsubstituted alkyl and substituted orunsubstituted aryl, may be selected from nitro, hydrogen, amino,substituted amino, carboxylic acid, sulfonic acid, methoxy, chloro,bromo, ester groups such as --CO₂ CH₃, keto groups such as --COCH₃, or--NHCOCH₃, --CONHCH₃, --NHSO₂ CH₃, or --SO₂ NHCH₃.

The X--Rel² and T² are preferably groups as described in U.S. Pat. Nos.4,409,323 and 4,959,299 that enables release of T² --INH from X--Rel²and INH from T² --INH by means of an electron transfer, preferably by anethylenic conjugated chain.

A typical coupler (A) of Class 2 of the Invention is a naphtholiccoupler represented by the formula: ##STR6## wherein; R¹⁹ is hydrogen,CH₃, methoxyphenyl, hydroxyethoxyphenyl, carboxyphenyl, --CH₂ CO₂ CH₃,--CH₂ CH₂ COOH or --CH₂ OCH₂ CH₂ COOH;

R²⁰ is a photographic ballast or a substituent which does notsubstantially delay release of T² --INH from X--Rel² ;

R²¹ and R²² are selected from hydrogen, substituted or unsubstitutedalkyl or substituted or unsubstituted aryl or a photographic ballast andare chosen not to substantially delay release of T² --INH from X--Rel² ;

R²³ is nitro. Other groups which may be considered in place of nitro arehydrogen, amino, carboxylic acid, sulfonic acid, methoxy, chloro, bromo,ester groups such as --CO₂ CH₃, keto groups such as --COCH₃, or--NHCOCH₃, --CONHCH₃, --NHSO₂ CH₃, --SO₂ NHCH₃, or R²³, in combinationwith the timing group T², can constitute a substituted or unsubstitutedpyridyl moiety.

R²⁴ and R²⁵ are selected from hydrogen, substituted or unsubstitutedalkyl or substituted or unsubstituted aryl and are chosen not tosubstantially delay release of T² --INH from X--Rel² ;

INH is a heterocyclic development inhibitor group.

An especially preferred naphtholic coupler is represented by thestructures I-13 through I-16, of table 2. While the invention has beendescribed with respect to naphtholic couplers, it has application toother couplers such as yellow, or magenta dye forming couplers.

CLASS 3

In the third invention a photographic element as noted, is providedcomprising a support bearing at least one photographic silver halideemulsion layer and at least one coupler (A) having a water solubilizinggroup wherein coupler (A) is capable of forming a compound that iswashed out of the photographic element during photographic processing.Coupler (A) has a coupling-off group represented by the formula:

    --X--REL.sup.3 --T.sup.3 --INH

wherein;

X is selected from oxygen, nitrogen or sulfur

X--Rel³ contains a photographic ballast and is a releasing group forreleasing T³ --INH from X--Rel³ by intramolecular displacement reactionduring photographic processing without substantial delay of releasing;

T³ is a timing group that releases INH by intramolecular displacementreaction with timing delay during photographic processing;

INH is a development inhibitor group.

The X--Rel³ as described is any X--Rel³ releasing group which releasesT³ --INH from X--Rel³ by an intramolecular displacement reaction duringphotographic processing without substantial delay of releasing. TheX--Rel³ as described, is not a timing group that substantially delaysrelease of T³ --INH. The X--Rel³ can serve as a carrier for aphotographic ballast group for the coupler prior to exposure andphotographic processing.

A typical X--Rel³ group is represented by the formula: ##STR7## wherein;Z¹ represents the atoms necessary to complete a 5 or 6 member aryl orheterocyclic group;

R²⁶ is hydrogen or a substituent which does not substantially delayrelease of T³ --INH;

R²⁷ and R²⁸ is selected from hydrogen, substituted or unsubstitutedalkyl, and substituted or unsubstituted aryl;

R²⁹ is unsubstituted or substituted alkyl or substituted orunsubstituted aryl;

R²⁶, R²⁷, R²⁸ and R²⁹ are chosen not to substantially delay release ofT³ --INH from X--Rel³ ;

at least one of R²⁶, R²⁷, R²⁸ and R²⁹ can be a photographic ballastgroup;

n is 0, 1 or 2.

A substituent which does not substantially delay release of T³ --INH,and the substituted or unsubstituted alkyl and substituted orunsubstituted aryl, may be selected from nitro, hydrogen, amino,substituted amino, carboxylic acid, sulfonic acid, methoxy, chloro,bromo, ester groups such as --CO₂ CH₃, keto groups such as --COCH₃, or--NHCOCH₃, --CONHCH₃, --NHSO₂ CH₃, or --SO₂ NHCH₃.

The T³ as described is any timing group that releases INH by anintramolecular displacement reaction that enables a time delay betweenthe oxidative coupling of the coupler (A) and the release of INH. The T³differs from the X--Rel³ in that T³ enables time delay whereas X--Rel³does not enable substantial time delay.

A typical T³ is represented by the formula: ##STR8## wherein; R³⁰ ishydrogen or a substituent which does not substantially delay release ofT³ --INH from X--Rel³, R³⁰, R³¹, R³² and R³³ are chosen to provide aminimum time delay of at least 5 seconds.

R³¹ and R³² is selected from hydrogen, substituted or unsubstitutedalkyl or substituted or unsubstituted aryl;

R³³ is unsubstituted or substituted alkyl or substituted orunsubstituted aryl;

R³⁰, R³¹, R³² and R³³ are chosen not to substantially delay release ofT³ --INH from X--Rel³ ;

Z² represents the atoms necessary to complete a 5 or 6 member arylene orheterocyclic group.

n is 0, 1 or 2.

A substituent which does not substantially delay release of T³ --INH,and the substituted or unsubstituted alkyl and substituted orunsubstituted aryl, may be selected from nitro, hydrogen, amino,substituted amino, carboxylic acid, sulfonic acid, methoxy, chloro,bromo, ester groups such as --CO₂ CH₃, keto groups such as --COCH₃, or--NHCOCH₃, --CONHCH₃, --NHSO₂ CH₃, or --SO₂ NHCH₃.

The X--Rel³ and T³ are preferably groups as described in U.S. Pat. No.4,248,962 that enables release of T³ --INH from X--Rel³ and INH from T³--INH by means of an intramolecular displacement.

A typical coupler (A) of Class 3 of the Invention is a naphtholiccoupler represented by the formula: ##STR9## wherein; R³⁴ is hydrogen,CH₃, methoxyphenyl, hydroxyethoxyphenyl, carboxyphenyl, --CH₂ CO₂ CH₃,--CH₂ CH₂ COOH or --CH₂ OCH₂ CH₂ COOH;

R³⁵ is a photographic ballast, hydrogen, or a substituent which does notsubstantially delay release of T³ --INH from X--Rel³ ;

R³⁶ and R³⁷ is selected from hydrogen, substituted and unsubstitutedalkyl containing 1 to 3 carbon atoms, or substituted or unsubstitutedaryl, and a photographic ballast;

R³⁸ is selected from substituted and unsubstituted alkyl containing 1 to3 carbon atoms, or substituted or unsubstituted aryl, and a photographicballast;

R³⁹ is nitro. Other groups which may be considered in place of nitro arehydrogen, amino, carboxylic acid, sulfonic acid, methoxy, chloro, bromo,ester groups such as --CO₂ CH₃, keto groups such as --COCH₃, or--NHCOCH₃, --CONHCH₃, --NHSO₂ CH₃, --SO₂ NHCH₃, or R³⁹, in combinationwith the timing group T³, can constitute a substituted or unsubstitutedpyridyl moiety;

R⁴⁰ and R⁴¹ is selected from hydrogen, substituted and unsubstitutedalkyl containing 1 to 3 carbon atoms, or substituted or unsubstitutedaryl;

R⁴² is selected from substituted and unsubstituted alkyl containing 1 to3 carbon atoms, or substituted or unsubstituted aryl;

n and m are individually 0, 1 or 2.

A substituent which does not substantially delay release of T³ --INH,and the substituted or unsubstituted alkyl and substituted orunsubstituted aryl, may be selected from nitro, hydrogen, amino,substituted amino, carboxylic acid, sulfonic acid, methoxy, chloro,bromo, ester groups such as --CO₂ CH₃, keto groups such as --COCH₃, or--NHCOCH₃, --CONHCH₃, --NHSO₂ CH₃, or --SO₂ NHCH₃.

INH is a heterocyclic development inhibitor group.

An especially preferred naphtholic coupler is represented by thestructures I-17 through I-21, of table 3. While the invention has beendescribed with respect to naphtholic couplers, it has application toother couplers such as yellow, or magenta dye forming couplers.

CLASS 4

In the fourth invention a photographic element as noted, is providedcomprising a support bearing at least one photographic silver halideemulsion layer and at least one coupler (A) having a water solubilizinggroup wherein coupler (A) is capable of forming a compound that iswashed out of the photographic element during photographic processing.Coupler (A) has a coupling-off group represented by the formula:

    --X--REL.sup.4 --T.sup.4 --INH

wherein;

X is selected from oxygen, nitrogen or sulfur

X--Rel⁴ is a releasing group for releasing T⁴ --INH from X Rel⁴ byelimination electron transfer reaction during photographic processingwithout substantial delay of releasing;

T⁴ is a timing group that releases INH by intramolecular displacementreaction with timing delay during photographic processing;

INH is a development inhibitor group.

The X--Rel⁴ as described is any X--Rel⁴ releasing group which releasesT⁴ --INH from X--Rel⁴ by an elimination electron transfer reactionduring photographic processing without substantial delay of releasing.The X--Rel⁴ as described is not a timing group that delays release of T⁴--INH. The X--Rel⁴ can serve as a carrier for a photographic ballastgroup for the coupler prior to exposure and photographic processing.

A typical X--Rel⁴ group is represented by the formula: ##STR10##wherein; R⁴³ is hydrogen or a substituent which does not substantiallydelay release of T⁴ --INH;

R⁴⁴ and R⁴⁵ is selected from hydrogen, substituted or unsubstitutedalkyl, and substituted or unsubstituted aryl and are selected not tosubstantially delay release of T⁴ --INH;

R⁴³, R⁴⁴ and R⁴⁵ can be a photographic ballast and are selected not tosubstantially delay release of T⁴ --INH; and

Z¹ represents the atoms necessary to complete a 5 or 6 member aryl orheterocyclic group.

A substituent which does not substantially delay release of T⁴ --INH,and the substituted or unsubstituted alkyl and substituted orunsubstituted aryl, may be selected from nitro, hydrogen, amino,substituted amino, carboxylic acid, sulfonic acid, methoxy, chloro,bromo, ester groups such as --CO₂ CH₃, keto groups such as --COCH₃, or--NHCOCH₃, --CONHCH₃, --NHSO₂ CH₃, or --SO₂ NHCH₃.

The T⁴ as described is any timing group that releases INH by anintramolecular displacement reaction that enables a time delay betweenthe oxidative coupling of the coupler (A) and the release of INH. The T⁴differs from the X--Rel⁴ in that T⁴ enables time delay whereas X--Rel⁴does not enable substantial time delay.

A typical T⁴ is represented by the formula: ##STR11## wherein Z²represents the atoms necessary to complete a 5 or 6 member arylene orheterocyclic group;

R⁴⁶ is hydrogen or a substituent which does not substantially delayrelease of T⁴ --INH from X--Rel⁴ ;

R⁴⁷ and R⁴⁸ are selected from hydrogen, substituted or unsubstitutedalkyl or substituted or unsubstituted aryl;

R⁴⁹ is unsubstituted or substituted alkyl or substituted orunsubstituted aryl;

R⁴⁶, R⁴⁷, R⁴⁸ and R⁴⁹ are chosen to provide a minimum time delay of atleast 5 seconds; and

n is 0, 1, or 2.

A substituent which does not substantially delay release of T⁴ --INH,and the substituted or unsubstituted alkyl and substituted orunsubstituted aryl, may be selected from nitro, hydrogen, amino,substituted amino, carboxylic acid, sulfonic acid, methoxy, chloro,bromo, ester groups such as --CO₂ CH₃, keto groups such as --COCH₃, or--NHCOCH₃, --CONHCH₃, --NHSO₂ CH₃, or --SO₂ NHCH₃.

The X--Rel⁴ is preferably a group as described in U.S. Pat. Nos.4,409,323 and 4,959,299, that enables release of T⁴ --INH from X--Rel⁴by means of electron transfer and T⁴ is preferably a group as describedin U.S. Pat. No. 4,248,962 that enables release of INH from T⁴ by meansof intramolecular displacement.

A typical coupler (A) of Class 4 of the Invention is a naphtholiccoupler represented by the formula: ##STR12## wherein; R⁵⁰ is hydrogen,CH₃, methoxyphenyl, hydroxyethoxyphenyl, carboxyphenyl, --CH₂ CO₂ CH₃,--CH₂ CH₂ COOH or --CH₂ OCH₂ CH₂ COOH;

R⁵¹ is hydrogen, or a substituent which does not substantially delayrelease of T⁴ --INH from X--Rel⁴ ;

R⁵² and R⁵³ is selected from hydrogen, substituted and unsubstitutedalkyl, or substituted or unsubstituted aryl;

R⁵⁴ is nitro. Other groups which may be considered in place of nitro arehydrogen, amino, carboxylic acid, sulfonic acid, methoxy, chloro, bromo,ester groups such as --CO₂ CH₃, keto groups such as --COCH₃, or--NHCOCH₃, --CONHCH₃, --NHSO₂ CH₃, --SO₂ NHCH₃, or R⁵⁴, in combinationwith the timing group T⁴, can constitute a substituted or unsubstitutedpyridyl moiety;

R⁵⁵ and R⁵⁶ is selected from hydrogen, substituted and unsubstitutedalkyl, or substituted or unsubstituted aryl;

R⁵⁷ is selected from substituted and unsubstituted alkyl containing 1 to3 carbon atoms or substituted or unsubstituted aryl;

R⁵¹, R⁵² or R⁵³ contains a photographic ballast;

R⁵¹, R⁵², R⁵³, R⁵⁴, R⁵⁵, R⁵⁶ and R⁵⁷ are selected as not tosubstantially delay release of T⁴ --INH from X--Rel⁴ ;

n and m are individually 0, 1, or 2;and

INH is a heterocyclic development inhibitor group.

An especially preferred naphtholic coupler is represented by thestructures I-22 through I-25, of table 4. While the invention has beendescribed with respect to naphtholic couplers, it has application toother couplers such as yellow, or magenta dye forming couplers.

Delay of release as measured by half-life can extend to, but not beyondthe normal period of time required for developing the photographicelement. That is, in the present invention at least half of the INH thatis coupled off must be released at the end of the developing period.Delay of release of INH is usually not less than about 5 seconds,preferably is in the range of 5 to 600 seconds and typically in therange of 10 to 100 seconds. This can be determined in most cases in anaqueous solution at pH 10 or pH 14.

In the present invention, release of the timing group in the developmentof a photographic element is without substantial delay. Release of thetiming group (as measured by half-life), can occur in not normallygreater than 5 seconds, preferably less than 2 to 3 seconds, andtypically less than 1 second half-life. As noted, the half-life can bedetermined in most cases in an aqueous solution at pH 10 or pH 14.

By "aqueous solution at pH 10" is meant an aqueous solution containing3% Triton X--100, (a non-ionic surfactant, available from the AldrichChemical Co., Milwaukee, Wis.), at 23° C. and pH adjusted to 10 usingphosphate buffer.

By "aqueous solution at pH 14" is meant an solution containing 45%acetonitrile and 55% aqueous 0.1 N potassium hydroxide at 23° C.

A coupler moiety to which the coupling-off group is attached ispreferably a cyan, magenta or yellow dye-forming coupler moiety.Acetanilide and naphthol couplers are highly preferred.

As used herein the term "coupler" refers to the entire compound,including the coupler moiety (COUP), and the coupling-off groupincluding the INH. The term "coupler moiety" refers to that portion ofthe compound other than the coupling-off group.

A process of forming an image having the described advantages comprisesdeveloping an exposed photographic element by means of a colordeveloping agent in the presence of described coupler (A).

The water solubilizing group (SOL) can be any water solubilizing groupknown in the photographic art to enable wash-out of the dye formed inphotographic processing from the coupler (A). Typical water-solubilizinggroups include groups terminated with an acid group, such as carboxy,sulfo or hydroxy which may also form a salt and other groups describedin U.S. Pat. No. 4,482,629 (col. 4, lines 1-3). The coupler (A) can haveone or more water-solubilizing groups. The number and type of watersolubilizing groups should not be sufficient to make the coupler (A)mobile in the photographic element prior to exposure and processing.

A typical water-solubilizing group (SOL) is a carbonamido group--CONHR_(a) wherein R_(a) is hydrogen, an alkyl group containing 1 to 3carbon atoms, preferably --CONHCH₃ or --CONHC₂ H₅ ; or a groupcontaining a water solubilizing group, such as carboxy, sulfo or hydroxygroups, for instance, --CONH₂ CH₂ CH₂ OH, --CONH₂ CH₂ CO₂ H, or --CONH₂CH₂ CH₂ CO₂ H. Such a group can be, for example, in the 2-position of anaphtholic coupler containing the coupling-off group in the couplingposition.

INH can be any releasable development inhibitor group. Typical INHgroups are described in, for example U.S. Pat. Nos. 4,477,563;4,782,012; 4,886,736; 4,912,024; 4,959,299; and 5,026,628; thedisclosures of which are incorporated herein by reference. Preferreddevelopment inhibitor groups are heterocyclic inhibitor groups which forexample, include mercaptotetrazoles, mercaptoxadiazoles,mercaptothiadiazoles and benzotriazoles. Structures A-1 through A-8 asfollows, represent typical releasable development inhibitor groups.##STR13## wherein: R_(b), R_(e), R_(h), and R_(i) are individuallyhydrogen, substituted or unsubstituted alkyl of 1 to 8 carbon atoms suchas methyl, ethyl, propyl, butyl, 1-ethylpentyl, 2-ethoxyethyl,substituted phenyl, unsubstituted phenyl; substituted or unsubstitutedphenyl of 6 to 10 carbon atoms; alkylthio, such as methyl, ethyl,propyl, butyl or octylthio; or alkyl esters such as --CO₂ CH₃, --CO₂ C₂H₅, --CO₂ C3H7, --CO₂ C₄ H₉, --CH₂ CO₂ CH₃, --CH₂ CO₂ C₂ H₅, --CH₂ CO₂C₃ H₇, --CH₂ CO₂ C₄ H₉, CH₂ CH₂ CO₂ CH₃, --CH₂ CH₂ CO₂ C₂ H₅, --CH₂ CH₂CO₂ C₃ H₇, and --CH₂ CH₂ CO₂ C₄ H₉ ; or aryl esters such as --CO₂ R_(j),--CH₂ CO₂ R_(j), --CH₂ CH₂ CO₂ R_(j), wherein R_(j) is substituted orunsubstituted aryl;

wherein:

R_(c), R_(d), R_(f), and R_(g) are as described for R_(b), R_(e), R_(h),and R_(i) ; or, are individually one or more halogen such as chloro,fluoro, or bromo; carboxyl, esters or other substituents such as--NHCOCH₃, --SO₂ OCH₃, --OCH₂ CH₂ SO₂ CH₃, --OCOCH₂ CH₃, --NHCOCH₃ ornitro groups.

As used herein the term photographic ballast group (BALL) is a ballastgroup that is known in the photographic art. The ballast group asdescribed is an organic group of such size and configuration as toconfer on the molecule sufficient bulk to render the moleculesubstantially non-diffusible from the layer in which it is coated in aphotographic element. Representative ballast groups include substitutedor unsubstituted alkyl or aryl groups typically containing 8 to 40carbon atoms. The ballast group as described, is located on X--Rel¹ andcan be either R⁹ or R¹⁰.

A process of forming an image having the described advantages comprisesdeveloping an exposed photographic element by means of a colordeveloping agent in the presence of described coupler (A), as described.

A preferred coupler (A) is an acetanilide or naphtholic coupler.

The coupler moiety (COUP) can be any moiety having a water solubilizinggroup, provided that the coupler moiety will react with oxidized colordeveloping agent to cleave the bond between the X--Rel (RELEASING GROUP)portion of the coupling-off group and the coupler moiety. The couplermoiety herein includes coupler moieties employed in conventionalcolor-forming couplers that yield colorless products on reaction withoxidized color developing agents as well as coupler moieties that yieldcolored products on reaction with oxidized color developing agents. Bothtypes of coupler moieties are known to those skilled in the photographicart.

The coupler moiety can be ballasted or unballasted provided that the dyeformed upon oxidative coupling is capable of being washed out of thephotographic element. It can be monomeric, or it can be part of adimeric, oligomeric or polymeric coupler, in which case more that onegroup containing PUG can be contained in the coupler, or it can formpart of a bis compound in which the INH forms part of a link between twocoupler moieties.

The INH can be any of the mentioned heterocyclic inhibitor groups thatis typically made available in a photographic element in an imagewisefashion. Combinations of couplers, such as combinations of couplers (A),are also useful. Combinations of at least one coupler (A) with othercouplers that are capable of releasing a reagent or a photographic dyeare useful. A photographic reagent herein is a moiety that upon releasefurther reacts with components in the photographic element, such asdevelopment inhibitor, a development accelerator, a bleach inhibitor, ableach accelerator, a coupler (for example, a competing coupler, adye-forming coupler, or a development inhibitor releasing coupler (DIRcoupler)), a dye precursor, a dye, a developing agent (for example, acompeting developing agent, a dye-forming developing agent, or a silverhalide developing agent), a silver complexing agent, a fixing agent, animage toner, a stabilizer, a hardener, a tanning agent, a fogging agent,an ultraviolet radiation absorber, an antifoggant, a nucleator, achemical or spectral sensitizer or a desensitizer.

The INH can be present in the coupling-off group as a preformed speciesor it can be present in a blocked form or as a precursor.

There follows a listing of patents and publications that describerepresentative couplers that are useful with couplers of the inventionand coupler moieties useful in the coupler (A) of the invention:

I. COUP's

A. Couplers which form cyan dyes upon reaction with oxidized colordeveloping agents are described in such representative patents andpublications as: U.S. Pat. Nos. 2,772,162; 2,895,826; 3,002,836;3,034,892; 2,474,293; 2,423,730; 2,367,531; 3,041,236; 4,333,999 and"Farbkuppler-eine Literaturubersicht," published in Agfa Mitteilungen,Band III, pp. 156-175 (1961).

Preferably such couplers are phenols and naphthols which form cyan dyeson reaction with oxidized color developing agent.

B. Couplers which form magenta dyes upon reaction with oxidized colordeveloping agent are publications as: U.S. Pat. Nos. 2,600,788;2,369,489; 2,343,703; 2,311,082; 3,152,896; 3,519,429; 3,062,653;2,908,573 and "Farbkuppler-eine Mitteilungen, Band III, pp. 126-156(1961).

Preferably such magenta dye-forming couplers are pyrazolones orpyrazolotriazole couplers.

C. Couplers which form yellow dyes upon reaction with oxidized and colordeveloping agent are described in such representative patents andpublications as: U.S. Pat. Nos. 2,875,057; 2,407,210; 3,265,506;2,298,443; 3,048,194; 3,447,928 and "Farbkuppler-eine Mitteilungen, BandIII, pp. 112-126 (1961).

Preferably such yellow dye-forming couplers are acylacetamides, such asbenzoylacetamides and pivaloylacetamides.

D. Couplers which form colorless products upon reaction with oxidizedcolor developing agent are described in such representative patents as:U.K. Patent No. 861,138; U.S. Pat. Nos. 3,632,345; 3,928,041; 3,958,993and 3,961,959.

The photographic couplers of the invention can be incorporated inphotographic elements by means and processes known in the photographicart. In a photographic element prior to exposure and processing thephotographic coupler should be of such size and configuration that itwill not diffuse through the photographic layers.

Photographic elements of this invention can be processed by conventionaltechniques in which color forming couplers and color developing agentsare incorporated in separate processing solutions or compositions or inthe element.

Photographic elements in which the couplers of this invention areincorporated can be a simple element comprising a support and a singlesilver halide emulsion layer or they can be multilayer, multicolorelements. The couplers of this invention can be incorporated in at leastone of the silver halide emulsion layers and/or in at least one otherlayer, such as an adjacent layer, where they will come into reactiveassociation with oxidized color developing agent which has developedsilver halide in the emulsion layer. The silver halide emulsion layercan contain or have associated with it, other photographic couplercompounds, such as dye-forming couplers, colored masking couplers,and/or competing couplers. These other photographic couplers can formdyes of the same or different color and hue as the photographic couplersof this invention. Additionally, the silver halide emulsion layers andother layers of the photographic element can contain addendaconventionally contained in such layers.

A typical multilayer, multicolor photographic element can comprise asupport having thereon a red-sensitive silver halide emulsion unithaving associated therewith a cyan dye image-providing material, agreen-sensitive silver halide emulsion unit having associated therewitha magenta dye image-providing material and a blue-sensitive silverhalide emulsion unit having associated therewith a yellow dyeimage-providing material, at least one of the silver halide emulsionunits having associated there with a photographic coupler of theinvention. Each silver halide emulsion unit can be composed of one ormore layers and the various units and layers can be arranged indifferent locations with respect to one another.

The couplers of this invention can be incorporated in or associated withone or more layers or units of the photographic element. For example, alayer or unit affected by PUG can be controlled by incorporating inappropriate locations in the element a scavenger layer which willconfine the action of PUG to the desired layer or unit. At least one ofthe layers of the photographic element can be, for example, a mordantlayer or a barrier layer.

The light sensitive silver halide emulsions can include coarse, regularor fine grain silver halide crystals or mixtures thereof and can becomprised of such silver halides as silver chloride, silver bromide,silver bromoiodide, silver chlorobromide, silver chloroiodide, silverchlorobromoiodide and mixtures thereof. The emulsions can benegative-working or direct-positive emulsions. They can form, latentimages predominantly on the surface of the silver halide grains orpredominantly on the interior of the silver halide grains. They can bechemically and spectrally sensitized. The emulsions typically will begelatin emulsions although other hydrophilic colloids are useful.Tabular grain light sensitive silver halides are particularly usefulsuch as described in Research Disclosure, January 1983, Item No. 22534,and U.S. Pat. No. 4,434,226.

The support can be any support used with photographic elements. Typicalsupports include cellulose nitrate film, cellulose acetate film,polyvinylacetal film, polyethylene terephthalate film, polycarbonatefilm and related films or resinous materials as well as glass, paper,metal and the like. Typically, a flexible support is employed, such as apolymeric film or paper support. Paper supports can be acetylated orcoated with baryta and/or an α-olefin polymer, particularly a polymer ofan α-olefin containing 2 to 10 carbon atoms such as polyethylene,polypropylene, ethylene-butene copolymers and the like.

The coupler (A) can be used in photographic elements in the same way asphotographic couplers which release mercaptotetrazole inhibitor groupshave previously been used in photographic elements. However, because ofthe improved ability to control the release of the INH the couplerspermit enhanced effects or more selective effects.

In the following discussion of suitable materials for use in theemulsions and elements of this invention, reference will be made toResearch Disclosure, December 1978, Item 17643, published by IndustrialOpportunities Ltd., Homewell Havant, Hampshire, P09 1EF, U.K., thedisclosures of which are incorporated herein by reference. Thispublication will be identified hereafter by the term "ResearchDisclosure".

The photographic elements can be coated on a variety of supports asdescribed in Research Disclosure Section XVII and the referencesdescribed therein.

Photographic elements can be exposed to actinic radiation, typically inthe visible region of the spectrum, to form a latent image as describedin Research Disclosure Section XVIII and then processed to form avisible dye image as described in Research Disclosure Section XIX.Processing to form a visible dye image includes the step of contactingthe element with a color developing agent to reduce developable silverhalide and oxidize the color developing agent. Oxidized color developingagent in turn reacts with the coupler to yield a dye.

Preferred color developing agents useful in the invention arep-phenylene diamines. Especially preferred are4-amino-N,N-diethylaniline hydrochloride;4-amino-3-methyl-N,N-diethylaniline hydrochloride;4-amino-3-methyl-N-ethyl-N-β-(methanesulfonamido)ethylaniline sulfatehydrate; 4-amino-3-methyl-N-ethyl-N-β-hydroxyethylaniline sulfate;4-amino-3-β-(methanesulfonamido)-ethyl-N,N-diethlaniline hydrochloride;and 4-amino-N-ethyl-N-(2-methoxyethyl)-m-toluidine di-p-toluenesulfonicacid.

The described photographic materials and processes can be used withphotographic silver halide emulsions and addenda known to be useful inthe photographic art, as described in, for example, Research Disclosure,December 1989, Item No. 308,119, the disclosures of which areincorporated herein by reference.

With negative working silver halide the processing step described abovegives a negative image. To obtain a positive (or reversal) image, thisstep can be preceded by development with a non-chromogenic developingagent to develop exposed silver halide, but not form a dye, and thenuniformly fogging the element to render unexposed silver halidedevelopable. Alternatively, a direct positive emulsion can be employedto obtain a positive image.

Development is followed by the conventional steps of bleaching, fixing,or bleach-fixing, to remove silver and silver halide, washing anddrying.

Representative compounds of the invention can be prepared as follows:##STR14##

COMPOUND (2)

2-fluoro-5-nitroaniline (75g, 0.48Mole), (1) was taken up in THF (750mL). This solution was cooled to 0° C. and trifluoroacetic anhydride(130 mL, 0.933 Mole), was added fairly rapidly over a 30 minute period.At the end of the addition the yellow color of the amine had changed togive an orange solution. The reaction was stirred at room temperaturefor 8 hours. At the end of this period the solvent was removed underreduced pressure, the residue coevaporated with toluene, and the solidrecrystallized from toluene. The product, compound (2), was collected asan off white solid, 106 g (88%).

COMPOUND (3)

Compound (2), (103.5 g, 0.41 Mole) was taken up in acetone (500 mL). Tothis solution was added methyl iodide (187.6 g, 1.32 Mole) withstirring, followed by 85%-KOH, (94 g, 1.68 Mole). Stirring at roomtemperature was continued wherein the solution began to reflux. Afterabout 30-45 minutes the refluxing subsided and the temperature began tofall. Stirring was continued for about 1.5 hours. At the end of thisperiod the precipitated KI was filtered off and the filtrateconcentrated under reduced pressure. The residue so obtained was takenup in an ethyl acetate water mix, separated, and the ethyl acetate layerwashed with water (x3). The original layer was then dried (MgSO₄),filtered, and the solvent removed under reduced pressure. The crystalsso obtained were washed out of the flask with heptane. The productcompound (3), amounted to 122.5 g, (88%).

COMPOUND (4)

The mixed anhydride, prepared from acetic anhydride (8.3 mL) and formicacid (4.2 mL) at 0° C. over a 1 hour period, was added dropwise tocompound (3), (6.6 g, 38.76 mMole) in THF (50 mL) at 0° C. Thetemperature of the reaction was allowed to reach room temperature andthe solution stirred for 2 hours. At the end of this period the solutionwas concentrated to an oil under reduced pressure and taken up in ethylacetate. The ethyl acetate was then washed with 2.5% Na₂ CO₅ (x3),2N--Cl (x1), dried, (MgSO₄), filtered and the solution concentrated toan oil which slowly crystallized. Yield of compound (4), 5.0 g (65%).

COMPOUND (6)

1,4-dihydroxy-naphthalene-2-carboxamide, (5), (4.66 g, 22.94 mMole) wasdissolved in deoxygenated 10% aqueous DMSO (60 mL) and the solutionstirred under a nitrogen atmosphere. To this solution was then added85%-KOH (3.3 g, 50.08 mMole). The mixture was stirred for approximately15 minutes at room temperature to get complete dissolution. Thissolution was then cooled to 5° C. and compound (4), (5.0 g, 25.23 mMole)added all at once as a solid. Stirring was continued while thetemperature rose to approximately 10° C. After maintaining thetemperature in the range of 5°-10° C. for 15 minutes the reactionmixture was then poured into ice cold 2N--HCl, filtered, washed withwater and finally air dried. This gave compound (6), yield 8.5 g, (97%),in sufficient purity to be used in the next step.

COMPOUND (7)

Compound (6), (8.5 g, 22.29 mMole) was taken up in THF (50 mL) andmethyl alcohol (150 mL) added. Raney-Nickel catalyst which had beenprewashed with water (x3) and methyl alcohol (x3) was then added to thesolution and hydrogenation carried out at room temperature at 50 psi.During the hydrogenation the product crystallizes out but can beredissolved by the addition of more THF. After several hours, whenhydrogen up take had ceased, the catalyst was carefully filtered offwashing the residue with hot pyridine. On concentrating, the product,compound (7), crystallized out and was filtered off. Yield 7.83 g(100%).

COMPOUND (8)

Compound (7), (7.83 g, 22.29 mMole) was dissolved in dry pyridine (100mL) and n-hexadecylsulphonyl chloride (7.97 g, 24.52 mMole) added. Afterstirring the resulting solution for about 30 minutes a further batch ofthe n-hexadecylsulphonyl chloride (1.0 g) was added. After a further 30minutes the pyridine was concentrated under reduced pressure and theoily residue taken up in ethyl acetate which was washed with 2N--HCl(x3), dried, (MgSO₄), filtered and concentrated to an oil. When treatedwith acetonitrile the formamide of compound (8) crystallized out, wasfiltered off and air dried to yield 9.5 g (67%). The above formamide(8.0 g, 12.50 mMole) was dissolved in DMSO (20 mL) to which was added85%-KOH (8.24 g, 12.48 mMole) in water (20 mL). The resulting solutionwas heated on a steam bath for approximately 5 hours. At the end of thisperiod, the reaction solution was cooled, poured into 2 N--HCl andextracted with ethyl acetate. The ethyl acetate extracts were thenwashed with 2N--HCl (x1), dried, (MgSO₄), filtered, and concentratedunder reduced pressure. The product crystallized out before dryness, itwas filtered off washed with a little cold ethyl acetate and air dried.The product, compound (8), was obtained as an off white solid, yield 4.7g (62%).

COMPOUND (10)

Compound (8), (6.5 g, 10.62 mMole) was dissolved in THF (50 mL) and a12% solution of phosgene in toluene (26 mL, 31.87 mMole) added followedby N,N-diethylaniline (1.14 mL, 7.19 mMole). After stirring at roomtemperature for 15 minutes the solvent was removed under reducedpressure to give the crude carbamyl chloride of compound (8). Thiscarbamyl chloride was then used as such in the next step.

The above crude carbamyl chloride was dissolved in dry pyridine (60 mL)and 4-hydroxymethyl-2-nitrophenol (9), (1.97 g, 11.68 mMole) added andthe resulting solution stirred at room temperature for 3 hours. Thesolution was then concentrated under reduced pressure and the oil takenup in ethyl acetate, washed with 2N--HCl, (x3), dried, (MgSO₄),filtered, and once again concentrated to an oil. This oil was dissolvedin a mixture of ethyl acetate (50%), dichloromethane (10%) and heptane(40%) and pressure chromtographed over silica gel eluting with the samesolvent mixture. The major band was collected to yield compound (10),7.5 g, (88%).

COMPOUND (11)

Compound (10), (7.0 g, 8.67 mMole) was dissolved in dry ether (100 mL)and phosphorus tribromide (0.9 mL, 9.54 mMole) in ether (10 mL) wasadded dropwise. After the addition a solid had precipitated which wasdissolved by the addition of THF (20 mL). After stirring the reactionsolution at room temperature for 30 minutes it was concentrated and theoil taken up in ethyl acetate. The ethyl acetate solution was thenwashed with 2N--HCl (x1), dried, (MgSO₄), and taken to an oil onceagain. This oil, compound (11) was used such in the next step.

COMPOUND (12)--INVENTION I-1

The crude compound (11), (9,29 mMole) was dissolved in dry DMF (60 mL)and NaPMT (2.05 g, 10.22 mMole) added. After stirring this solution atroom temperature for 1 hour, it was poured into 2N--HCl and extractedwith ethyl acetate (x3). The ethyl acetate extracts were combined,washed with 2N--HCl (x3), 2.5%-Na2CO₃, (x1), 2N--HCl (x1), dried,(MgSO₄), filtered and concentrated to an oil. The oil was taken up in asolvent mixture of ethyl acetate (30%), dichloromethane (10%) andheptane (60%) and pressure chromtographed over silica gel eluting withthis solvent mixture of 30:10:60 and then changed to 40:10:50 to collectthe major band. Compound (12)--Invention I-1, was collected as a whitesolid, yield 7.0 g (78%).

Calculated for C₄₉ H₅₈ N₈ O₉ S₂ : %C 60.85, %H 6.04, %N 11.59 and %S6.63. Found %C 60.74, %H 6.01, %N 11.18 and %S 6.78. ##STR15##

COMPOUND (5)

Phenyl 1,4-dihydroxy-2-naphthoate (100 g, 356.78 mMole) was dissolved indeoxygenated tetrahydrofuran, (500 mL) and deoxygenated methanol, (500mL) added. To this solution, stirred at room temperature under anitrogen atmosphere, was added ammonium acetate, (50,0 g, 648.63 mMole)followed by concentrated ammonium hydroxide, (1.0 L). After stirring for3 hours the reaction solution was then poured into ice cold 2N--HCl,(4.0 L) and enough concentrated HCl added to bring the pH to 1.Theresulting product, compound (5), was filtered off, washed well withwater and air dried. This material was washed with dichloromethane andair dried again. Yield 62.0 g, (72%).

COMPOUND (13)

Compound (5), (50.0 g, 0.246 mMole) was dissolved in dry pyridine, (150mL) and acetonitrile, (75 mL) added. The solution was stirred and cooledto -5°-0° C. Ethyl chloroformate, (50 mL, 0.523 mMole) was then addeddropwise with stirring while maintaining the temperature at 0° C. Afterthe addition, the cooling bath was removed and the temperature allowedto reach room temperature. The reaction mixture was then graduallyheated to reflux and the solvent allowed to distill off. This procedurewas continued until the temperature had risen to approximately 120° C.and 150 mL of solvent had been collected. Heating under reflux wascontinued for an additional 1 hour period. The reaction mixture was thencooled to approximately 50° C. and poured into 2N--HCl (3.0 L) which wasmaintained at room temperature. The suspension was then stirred forapproximately 15 minutes, filtered and the residue washed well withwater, acetonitrile and finally ether. This gave the product, compound(13), sufficiently pure for the next step. Yield 43.5 g, (77%).

COMPOUND (15)

Compound (13), (23.0 g, 100.35 mMole) was taken up in deoxygenateddimethyl sulphoxide, (250 mL) and deoxygenated water, (25 mL) added. Tothis solution, stirred at room temperature under nitrogen, was added 85%potassium hydroxide, (9.9 g, 150.53 mMole) and stirring continued untildissolution, approximately 15 minutes. 4--Chloro-3-nitrobenzaldehyde(14), (18.62 g, 100.35 mMole), was then added all at once, and theresulting solution stirred at 60° C. for 1 hour. The reaction mixturewas then poured into ice cold 2N--HCl (2.0 L), and filtered off. Theproduct, compound (15), was washed with ether. This product was pureenough to be used in the next step. Yield 28.0 g (74%).

COMPOUND (16)

Compound (15), (28.0 g, 74.01 mMole), in a powdered form, was suspendedin tetrahydrofuran, (150 mL) and methanol, (100 mL). Water, (100 mL) wasadded followed by sodium borohydride, (2.8 g, 74.01 mMole) in smallportions. More tetrahydrofuran, (50 mL) was added to aid stirring. Atthe end of the sodium borohydride addition complete dissolution had beenachieved. The reaction was allowed to proceed for a further 15 minutes,then poured into ice cold 2N--HCl (2.0 L), and the product filtered off.The product was washed with methanol and while still wet with solvent,suspended in ethanol and heated to reflux. The solution was cooled,filtered, washed with methanol, ether and finally air dried. A secondcrop of material was obtained on concentrating the mother liquor. Totalyield of the benzyl alcohol precursor to compound (16), 19.5 g, (67%).

The latter compound, (19.0 g, 50 mMole) was suspended in water, (200mL), containing 85% potassium hydroxide, (26.34 g, 400 mMole). To thismixture was added methanol, (50 mL) and then heated to 80° C. for 1hour. The resulting dark yellow-brown solution was cooled and pouredinto ice cold 2N--HCl (2.0 L). The yellow product was filtered off,washed well with water and air dried. Yield of compound (16), 17.7 g(100%).

COMPOUND (17)

Compound (16), (17.7 g, 50 mMOle) was dissolved in tetrahydrofuran, (80mL) and methanol, (300 mL) added. Raney-Nickel which had been washedseveral times with water and then methanol, was added and the solutionhydrogenated at 55 psi. Hydrogen uptake had ceased after 2 hours. Thecatalyst was filtered off, washed with methanol and the filtrateconcentrated under reduced pressure to give the product. This product,the amino precursor to compound (17), was deemed sufficiently pure to becarried on to the next step. Yield 100%.

The above amino compound, (50.0 mMole) was dissolved in dry pyridine,(150 mL) and n-hexadecylsulphonyl chloride, (16.2 g, 50.0 mMole) added.The solution was stirred at room temperature under a nitrogen atmospherefor 30 minutes. The pyridine was concentrated under reduced pressure andthe residue taken up in ethyl acetate. This ethyl acetate solution 7 wasthen washed with 2N--HCl (x3), dried, (MgSO₄), filtered andconcentrated. The residue which resulted crystallized from acetonitrile.After filtering, washing with acetonitrile and drying, the yield ofproduct, compound (17), amounted to 16.3 g, {53% calculated fromcompound (16)}.

COMPOUND (18)

Compound (17), (4.0 g, 6.53 mMole) was suspended in dry ether, (30 mL)and phosphorous tribromide, (0.68 mL, 7.18 mMole) in ether, (20 mL)added dropwise over a 15 minute period. After the addition the reactionwas diluted with ether and the ether solution washed with 2N--HCl (x1),dried, (MgSO₄), filtered and concentrated to give compound (18). Theyield was 100%.

COMPOUND (20)

Compound (18), (13.5 g, 19.98 mMole) was dissolved in DMF, (100 mL), and4-hydroxy-3-nitrobenzaldehyde (19), (3.34 g, 19.98 mMole) followed by2,6-lutidine, (4.64 mL, 40 mMole) were added. The reaction solution wasstirred at room temperature for 24 hours. A further batch of base, (4.64mL), was added and the reaction solution stirred for a further 24 hours.After this period the temperature of the reaction was raised to 60° C.and held there with stirring for a further 24 hours. At the end of thisperiod the reaction was worked up by dilution with ethyl acetate andwashing the ethyl acetate layer with 2N--HCl (x2), 2%-Na2C₀₃ (x3),2N--HCl (x1), dried (MgSO₄), filtered and concentrated under reducedpressure to an oil. This oil was dissolved in a solvent mixture of ethylacetate (20), dichloromethane (5) and heptane (30), and pressurechromotographed over silica gel eluting with the same solvent mixture.Three major components were collected in the following order ofincreasing polarity; the formulated derivative of compound (17), theproduct, compound (20), and the benzyl alcohol compound (17). The yieldof compound (20) was 3.4 g, (22%).

COMPOUND (21)

Compound (20), (9.5 g, 12.47 mMole) was dissolved in THF (30 mL), andmethyl alcohol (30 mL) added. Sodium borohydride (0.47 g, 12.47 mMole)was gradually added with stirring. After the sodium brohydride had beenadded the resulting solution was stirred at room temperature for 15minutes. The reaction solution was then concentrated, taken up in ethylacetate and the ethyl acetate solution washed with 2N--HCl (x1), dried(MgSO₄), filtered and concentrated to an oil under reduced pressure.This oil, compound (21), was used directly in the next step but can becrystallized form ether.

COMPOUND (22)

Compound (21), (12.47 mMole), was dissolved in a 50% solution of THF andether (100 mL). Phosphorus tribromide (1.2 mL, 12.47 mMole) in ether (20mL) was then added dropwise. At the end of the addition the reactionsolution was stirred at room temperature for 15 minutes. The reactionwas then diluted with ethyl acetate, washed with 2N--HCl (x1), brine(x1), dried (MgSO₄), filtered and concentrated to an oil. This oil,compound (22), was used directly in the next step of the sequence.

COMPOUND (23)--INVENTION I-13

Compound (22), (12.47 mMole) was dissolved in DMF (60 mL) and NaPMT,(2.5 g, 12.47 mMole) added. The reaction was stirred at room temperaturefor 15 minutes. It was then diluted with ethyl acetate, washed with2N--HCl (x1), 2.5% -Na2C₀₃ (x1), 2N--HCl (x1), brine (x1), dried(MgSO₄), filtered and concentrated under reduced pressure to an oil.This oil was dissolved in a solvent mixture of ethyl acetate (15),dichloromethane (5), and heptane (30) and pressure chromotographed oversilica gel eluting with the same solvent mixture. Yield of compound(23)--Invention I-13, 9.8 g (85%).

Calculated for C₄₈ H₅₇ O₈ S₂ : %C 62.38, %H 6.22, %N 10 61, %S 6.14.Found: %C 62.15, %H 6.23, %N 10.19, %S 7.21. ##STR16##

COMPOUND (25)

1,4-Dihydroxynaphthalene-2-carboxamide, (5), (10.0 g, 49.21 mMole) wasdissolved in deoxygenated DMSO, (300 mL) containing water (30 mL). Tothis solution, stirred under nitrogen, was added 85%-KOH (12.2 g, 0.184Mole) and stirring continued for a further 15 minutes. To the resultingdark coloured solution was added N-dodecyl-2-fluoro-5-nitroaniline,(24), (26.4 g, 0.081 Mole), all at once and the reaction mixture stirredat 600° C. for 2 hours. The reaction was then poured into 2N--HCl,treated with a small volume of ether and the resulting solid filteredoff. This solid was washed with methanol, then ether and air dried togive compound (25), 25.0 g, (100%). This product was pure enough to beused in the next step.

COMPOUND (26)

Compound (25), (24.6 g, 48.46 mMole) was dissolved in THF, (300 mL) andphosgene (96 mL of a 15% solution in toluene, 145.38 mMole) added all atonce. After stirring at room temperature for 15 minutes the reactionsolution was concentrated under reduced pressure. The resulting oil wasdissolved in ether and treated with an equal volume of heptane. Theyellow solid, compound (26) was filtered off, washed with heptane andair dried to give 22.0 g, (80%).

COMPOUND (27)

2-(N-ethyl)aminomethyl-4-nitrophenol (95.9 g, 0.412 Mole), was suspendedwith stirring, in acetonitrile (800 mL) and triethylamine (168.5 mL,1.22 Mole), gradually added. To this solution was then gradually addeddi-t-butyl dicarbonate (100.0 g, 0.458 Mole). The mixture was thenheated under gentle reflux for 18 hours. At the end of this period thereaction solution was cooled, poured into cold 2N--HCl (3.0 L), and thetan solid filtered off. The product, compound (27), was washed well withwater and air dried to give a 100% yield of product of sufficient purityto be used in the next step.

COMPOUND (28)

Compound (26), (16.2 g, 28.42 mMole) was dissolved in dry pyridine (100mL) and compound (27), (9.3 g, 31.26 mMole) added with stirring followedby triethylamine (4 mL, 28.42 mMole). The resulting dark yellow colouredsolution was stirred at room temperature under a nitrogen atmosphere for12 hours. The reaction solution was then concentrated under reducedpressure and the residue taken up in ethyl acetate. The ethyl acetatesolution was washed with 2N--HCl (x2), dried (MgSO₄), filtered andconcentrated under reduced pressure to an oil. This oil was dissolved in20% ethyl acetate in heptane and passed through a pad of silica geleluting with the same solvent mixture to remove traces of impurities andthe product then eluted from the silica gel with 30% ethyl acetate. Theproduct compound (28), was isolated as a yellow foam. Yield 23 g, (97%).

COMPOUND (29)

Compound (28) (4.5 g, 5.42 mMole), was dissolved in dichloromethane (30mL) and trifluoroacetic acid (20 mL) added. The reaction solution wasthen stirred at room temperature for 60 minutes. After this time thesolution was concentrated and dissolved in ethyl acetate. The ethylacetate solution was then washed with water (x3), dried (MgSO₄),filtered and concentrated to an oil. This oil, compound (29), was usedas such in the next step.

COMPOUND (30)

Compound (29) (5.42 mMole), as described above, was dissolved in THF (50mL) and phosgene (8 mLs of a 20% solution in toluene, 16.26 mMole) wasadded and the reaction mixture stirred at room temperature for 60minutes. At the end of this time the reaction solution was concentratedunder reduced pressure to give compound (30). This product was used assuch in the next step.

COMPOUND (31)--INVENTION I-17

Compound (30) (5.42 mMole), as described above, was dissolved in drypyridine (20 mL) and the sodium salt of phenyl mercaptotetrazole (1.2 g,5.96 mMole) added. The resulting solution was stirred at roomtemperature for 1 hour. At the end of this time the reaction solutionwas diluted with ethyl acetate, and the ethyl acetate solution washedwith 2N--HCl (x1), 2.5%-Na₂ CO₃ (x2), 2N--HCl (x1), dried (MgSO₄),filtered and concentrated to an oil under reduced pressure. The oil wasdissolved in 40% ethyl acetate in heptane and pressure chromatographedeluting with 30% ethyl acetate in heptane to give the product, compound(31)--Invention I-17. Yield 3.2 g, {63% from compound (28)}.

m/z: By FDMS molecular ion at 933. ##STR17##

COMPOUND (32)

Compound (8), (10.0 g, 16.34 mMole) was dissolved in THF (50 mL) and a12% solution of phosgene in toluene (40 mL, 49.03 mMole) added. Afterstirring at room temperature for 15 minutes the solvent was removedunder reduced pressure to give the crude carbamyl chloride of compound(8).

The above described carbamyl chloride (16.34 mMole), was dissolved inpyridine (100 mL) and compound (27) (5.33 g, 17.98 mMole), added. Theresulting reaction solution was stirred at room temperature for 1 hour.At the end of this period the solution was concentrated under reducedpressure and the residue dissolved in ethyl acetate. The ethyl acetatesolution was then washed with 2N--HCl (x1), dried (MgSO₄), filtered andconcentrated to an oil. This oil was dissolved in 30% ethyl acetate inheptane and pressure chromatographed over silica gel eluting with thesame solvent mixture to remove impurities and then the product compound(32), collected when the solvent was changed to 50% ethyl acetate inheptane. Yield 13.4 g, {88% from compound (8)}.

COMPOUND (33)

Compound (32) (12.0 g, 12.85 mMole), was dissolved in dichloromethane(20 mL) and 96%-formic acid (80 mL) added. The resulting reactionsolution was stirred at room temperature for 3 hours. At the end of thisperiod the solution was poured into water and extracted with ethylacetate. The ethyl acetate layer was collected, washed with water (x3),dried (MgSO₄), filtered and concentrated under reduced pressure to givecompound (33). Yield 9.5 g, (89%).

COMPOUND (34)--INVENTION I-20

Compound (33) (5.0 g, 6.00 mMole), was dissolved in THF (50 mL) and asolution of 20% phosgene in toluene (6.7 mL, 13.49 mMole) added and theresulting reaction solution stirred at room temperature for 2 hours. Atthe end of this period the solution was concentrated under reducedpressure to yield the carbamyl chloride of compound (33).

The above described carbamyl chloride (6.00 mMole), was dissolved inpyridine (40 mL). To this solution was added the cyclohexylamine salt ofn-propyl 2,5-dihydro-5-thioxo-1H-tetrazole-1-acetic acid (2.0 g, 6.59mMole) and the resulting solution stirred at room temperature for 2hours. At the end of this time the reaction solution was diluted withethyl acetate and this solution washed with 2N--HCl (x1), 2.5%-Na₂ CO₃(x3), 2N--HCl (x1), dried (MgSO₄), filtered and concentrated underreduced pressure. The residue was dissolved in 35% ethyl acetate inheptane and pressure chromatographed eluting with the same solventmixture to remove traces of impurities. Compound (34)--Invention I-20,was collected when the solvent was changed to 50% ethyl acetate inheptane. Yield 2.5 g, {39% from compound (33)}.

m/z: By FDMS molecular ion at 1061. ##STR18##

COMPOUND (36)

Compound (18) (14.0 g, 20.72 mMole), 2-hydroxy-5-nitrobenzaldehyde (35)(3.8 g, 22.74 mMole), potassium iodide (5,16 g, 31.08 mMole) and2,6-lutidine (4.8 mL, 41.4 mMole) were suspended in acetonitrile (100mL) and heated under nitrogen at 70° C. for 12 hours. At the end of thisperiod the reaction mixture was cooled, poured into 2N--HCl andextracted with ethyl acetate (x3). The ethyl acetate layers werecombined, washed with 2.5%-Na₂ CO₃ (x3), 2N--HCl (x1), dried (MgSO₄),filtered and concentrated under reduced pressure. The residual oil wasdissolved in a solvent mixture of ethyl acetate (15) heptane (35) anddichloromethane (5) and pressure chromatographed over silica gel elutingwith the same solvent mixture. This removed some impurities. The productcompound (36), was collected when the solvent was changed to 50% ethylacetate in heptane. Yield 7.0 g, (44%).

COMPOUND (37)

Compound (36) (8.0 g, 10.5 mMole), was suspended in methanol (80 mL) andjust enough THF added to bring about dissolution. To this solution wasadded isopropylamine (4.5 mL, 52.50 mMole) and the resulting reactionmixture heated to reflux on a steam bath for 4 hours. At the end of thistime the reaction was cooled to give the amine of compound (36).

Without isolation, the above described amine was cooled to 0° C. andwith good stirring treated gradually with sodium borohydride (0.4 g, 50mMole). After the sodium borohydride had been added the reaction mixturewas allowed to reach room temperature over a 30 minute period. Thereaction mixture was then poured into water (1 L) and with 2N--HCl thepH adjusted to 1. The resulting precipitate compound (37), was filteredoff, washed well with water and air-dried. Yield 8.0 g {(96%).fromcompound (36)}.

COMPOUND (38)

Compound (37) (4.0 g, 4.9 mMole), was dissolved in THF (40 mL) to whichwas then added a 20% solution of phosgene in toluene (7.4 mL, 14.9mMole), followed by N,N-dimethylaniline (0.63 mL, 4.9 mMole). Thereaction mixture was then stirred at room temperature for 30 minutes. Atthe end of this period the solvent was removed under reduced pressureand the residue, containing compound (38), was taken on to the next stepin the sequence. The yield was assumed to be 100%.

COMPOUND (39)--INVENTION I-23

The above described carbamyl chloride compound (38) (4.9 mMole), wasdissolved in dry pyridine (50 mL) and the cyclohexylamine salt ofn-propyl 2,5-dihydro-5-thioxo-1H-tetrazole-1-acetic acid (1.48 g, 4.9mMole) added. The resulting reaction solution was stirred at roomtemperature for 12 hours. At the end of this period the solvent wasremoved under reduced pressure and the residue dissolved in ethylacetate. The ethyl acetate solution was then washed with 2N--HCl (x1),2.5%-Na₂ CO₃ (x3), 2N--HCl (x1), dried (MgSO₄), filtered andconcentrated under reduced pressure. The resulting oil was dissolved in30% ethyl acetate in heptane and pressure chromatographed over silicagel eluting with the same solvent mixture. The major band was collectedto give compound (39)--Invention 23. Yield 0.9 g, {18%.from compound(37)}.

m/z: FDMS shows molecular ion as expected at 1032.

The following examples further illustrate the invention.

Photographic elements were prepared by coating the following layers on acellulose ester film support (amounts of each component are indicated inmg/m²)

Emulsion layer 1: Gelatin--2420; red sensitized silver bromoiodide (asAg)--1615; yellow image coupler dispersed in dibutyl phthalate (RECEIVERLAYER)

Interlayer: Gelatin--860; didodecylhydroquinone--113

Emulsion layer 2: Gelatin--2690; green sensitized silver bromoiodide (asAg)--1615; magenta image coupler dispersed in tritolyl phosphate; DIRcompound of Tables 1, 2, 3 and 4 dispersed in N,N-diethyl-dodecanamideand coated at a level sufficient to provide a contrast of 0.5 (half) ofthe original contrast after stepwise green light exposure and process(CAUSER LAYER)

Protective Overcoat Gelatin--5380; bisvinylsulfonylmethyl ether at 2%total gelatin.

Structures of the image couplers are as follows: ##STR19##

Strips of each element were exposed to green light through a graduateddensity step tablet, or through a 35% modulation fringe chart forsharpness measurements, and then developed 3.25 minutes at 38° C. in thefollowing color developer, stopped, washed, bleached, fixed, washed anddried.

    ______________________________________                                        Color Developer:                                                              ______________________________________                                        Distilled Water         800    mL                                             Sodium Metabisulfite    2.78   g                                              Sodium Sulfite, anhydrous                                                                             0.38   g                                              CD-4 (color developer)* 4.52   g                                              Potassium Carbonate, anhyd.                                                                           34.3   g                                              Potassium Bicarbonate   2.32   g                                              Sodium Bromide          1.31   g                                              Potassium Iodide        1.20   mg                                             Hydroxylamine Sulfate (HAS)                                                                           2.41   g                                              Diethylenetriaminepentacetic                                                                          8.43   g                                              acid, pentasodium salt                                                        (40% Soln.)                                                                   Distilled Water         to 1   L                                              Adjust pH to 10.0.                                                            ______________________________________                                         *CD-4 is 4amino-3-methyl-N-ethyl-N-beta-hydroxy-ethylaniline sulfate.    

Processed images were read with green light to determine the contrastand AMT acutance from plots of AMT acutance vs. the logarithm of thecontrast for variations in the coated level of each developmentinhibitor releasing (DIR) compound, the acutance was determined at acontrast of 0.5 compared to its original contrast without the presenceof the DIR compound. The acutance for the control DIR coupler wassubtracted from each AMT value to provide the relative sharpness valuereported as change in AMT in Tables 1, 2, 3, and 4. AMT calculationsemployed the following formula in which the cascaded area under thesystem modulation curve is shown in equation (21.104) on page 629 of the"Theory of the Photographic Process", 4th Edition, 1977, edited by T. H.James: AMT=100+66 Log[cascaded area/2.6696 M] wherein the magnificationfactor M is 3.8 for the 35 mm system AMT. The use of CMT acutance isdescribed by R. G. Gendron in "An Improved Objective Method of RatingPicture Sharpness: CMT acutance: in the Journal of SMPTE, Vol. 82, pages1009-12, (1973). AMT is a further modification of CMT useful forevaluation systems which include the viewing of a positive print madefrom a negative.

Interimage effect (the degree of color correction) was evaluated after adaylight exposure. Interimage effect, as reported in Tables 1, 2, 3, and4, was quantified as the ratio of the gamma (γ) of the green-sensitivelayer (causer) to that of the red-sensitive layer (receiver).

                  TABLE 1                                                         ______________________________________                                        (Coup - X - Rel.sup.1 -T.sup.1 - INH)                                                                   Change In                                                           Change In γCauser/γ                               DI(A)R          Acutance  Receiver                                            Coupler         (ΔAMT)                                                                            (ΔIIE)                                        ______________________________________                                        Control 1-A     0         0                                                   Comparison 1-B* 1.2       0.2                                                 Invention I-1   3.1       0.4                                                 Invention I-2   4.4       0.6                                                 Invention I-3   3.5       0.6                                                 Invention I-4   3.5       0.4                                                 Invention I-5   4.4       0.5                                                 Invention I-6   3.0       0.6                                                 Invention I-7   3.6       0.7                                                 Invention I-8   3.6       0.7                                                 Invention I-9   4.0       0.6                                                 Invention I-10  3.5       1.0                                                 Invention I-11  3.2       1.73                                                Invention I-12  2.9       0.32                                                ______________________________________                                         Example 33, Col 45, U.S. Pat. No. 4,861,701                              

                  TABLE 2                                                         ______________________________________                                        (Coup - X - Rel.sup.2 -T.sup.2 - INH)                                                                   Change In                                                           Change In γCauser/γ                               DI(A)R          Acutance  Receiver                                            Coupler         (ΔAMT)                                                                            (ΔIIE)                                        ______________________________________                                        Control 1-A     0         0                                                   Comparison 1-B  1.2       0.2                                                 Invention I-13  3.1       0.4                                                 Invention I-14  4.0       0.3                                                 Invention I-15  4.0       0.3                                                 Invention I-16  4.0       0.8                                                 ______________________________________                                    

                  TABLE 3                                                         ______________________________________                                        (Coup - X - Rel.sup.3 -T.sup.3 - INH)                                                                   Change In                                                           Change In γCauser/γ                               DI(A)R          Acutance  Receiver                                            Coupler         (ΔAMT)                                                                            (ΔIIE)                                        ______________________________________                                        Control 1-A     0         0                                                   Comparison 1-B  1.2       0.2                                                 Invention I-17  1.4       0.56                                                Invention I-18  6.0       0.56                                                Invention I-19  1.2       0.56                                                Invention I-20  4.0       0.56                                                Invention I-21  0.8       0.27                                                ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        (Coup - X - Rel.sup.4 -T.sup.4 - INH)                                                                   Change In                                                           Change In γCauser/γ                               DI(A)R          Acutance  Receiver                                            Coupler         (ΔAMT)                                                                            (ΔIIE)                                        ______________________________________                                        Control 1-A     0         0                                                   Comparison 1-B  1.2       0.2                                                 Invention I-22  1.4       0.26                                                Invention I-23  6.0       0.26                                                Invention I-24  2.1       0.40                                                Invention I-25  7.0       0.19                                                ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        (Coupler Stability)                                                           DI(A)R        % Loss After 2 Weeks                                            Coupler       (49° C./50% RH)                                          ______________________________________                                        Control 1-A   8.0                                                             Comparison 1-B                                                                              20.0                                                            Invention I-1 3.0                                                             Invention I-2 11.0                                                            Invention I-3 0.0                                                             Invention I-4 0.0                                                             Invention I-5 0.0                                                             Invention I-6 0.0                                                             Invention I-7 0.0                                                             Invention I-8 3.0                                                             Invention I-9 1.0                                                             Invention I-10                                                                              0.0                                                             Invention I-11                                                                              2.0                                                             Invention I-12                                                                              0.0                                                             Invention I-13                                                                              0.0                                                             Invention I-14                                                                              0.0                                                             Invention I-15                                                                              5.4                                                             Invention I-16                                                                              1.5                                                             ______________________________________                                         ##STR20##

                                      TABLE 1                                     __________________________________________________________________________    Couplers I-1 through I-12,                                                    __________________________________________________________________________    I-1 (Invention)                I-2 (Invention)                                                                ##STR21##                                     I-3 (Invention)                I-4 (Invention)                                 ##STR22##                                                                                                    ##STR23##                                     I-5 (Invention)                I-6 (Invention)                                 ##STR24##                                                                                                    ##STR25##                                     I-7 (Invention)                I-8 (Invention)                                 ##STR26##                                                                                                    ##STR27##                                                 I-9 (Invention)                                                                ##STR28##                                                                           I-10 (Invention)                                                               ##STR29##                                                 I-11 (Invention)               I-12 (Invention)                                ##STR30##                                                                                                    ##STR31##                                     __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________    Couplers I-13 through I-16,                                                   __________________________________________________________________________    I-13 (Invention)                                                               ##STR32##                                                                    I-14 (Invention)                                                               ##STR33##                                                                    I-15 (Invention)                                                               ##STR34##                                                                    I-16 (Invention)                                                               ##STR35##                                                                    __________________________________________________________________________

                                      TABLE 3                                     __________________________________________________________________________    Couplers I-17 through I-21,                                                   __________________________________________________________________________    I-17 (Invention)                                                               ##STR36##                                                                    I-18 (Invention)                                                               ##STR37##                                                                    I-19 (Invention)                                                               ##STR38##                                                                    I-20 (Invention)                                                               ##STR39##                                                                    I-21 (Invention)                                                               ##STR40##                                                                    __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________    Couplers I-22 through I-25,                                                   __________________________________________________________________________    I-22 (Invention)                                                               ##STR41##                                                                    I-23 (Invention)                                                               ##STR42##                                                                    I-24 (Invention)                                                               ##STR43##                                                                    I-25 (Invention)                                                               ##STR44##                                                                    __________________________________________________________________________

Further examples of couplers of the invention are as follows: ##STR45##

PMT herein means a phenylmercaptotetrazole group.

Ph herein means a phenyl group.

From Tables 1, 2, 3, 4 and 5 it can be seen that the compounds of theinvention give improved acutance, interlayer interimage and stabilityover the Control 1-A and the Comparison 1-B. That is for example, inTable 5 Couplers I-1 and I-3 showed no loss in stability.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be effected within the spirit and scope of theinvention.

What is claimed is:
 1. A photographic element comprising a supportbearing at least one photographic silver halide emulsion layer and atleast one coupler (A) having a water solubilizing group wherein coupler(A) forms a compound that is washed out of the photographic elementduring photographic processing and forms a coupling-off grouprepresented by the formula:

    --X--Rel.sup.2 --T.sup.2 --INH

wherein; X is selected from oxygen, nitrogen or sulfur; X--Rel² containsa photographic ballast and is a releasing group for releasing T² --INHfrom X--Rel² by elimination electron transfer reaction duringphotographic processing, wherein the half-life for release of T² --INHfrom X--Rel² is not greater than five seconds; T² is a timing group thatreleases INH by elimination electron transfer reaction duringphotographic processing, wherein the half-life for release of INH fromT² is at least five seconds; and INH is a development inhibitor group.2. A photographic element as in claim 1 wherein X--Rel² is representedby the formula: ##STR46## wherein; R¹³ is hydrogen or a substituent;R¹⁴and R¹⁵ is selected from hydrogen, substituted or unsubstituted alkyl,and substituted or unsubstituted aryl; and Z¹ represents the atomsnecessary to complete a 5 or 6 membered aryl or heterocyclic group.
 3. Aphotographic element as in claim 1 wherein R² is represented by theformula: ##STR47## wherein; R¹⁶ is hydrogen or a substituent R¹⁶, R¹⁷,and R¹⁸ are chosen to provide a minimum time delay of at least 5 secondshalf-life for release of INH from T² ;R¹⁷ and R¹⁸ are selected fromhydrogen, substituted or unsubstituted alkyl substituted orunsubstituted aryl; and Z² represents the atoms necessary to complete a5 or 6 member arylene or heterocyclic group.
 4. A photographic elementin accordance with claim 2, wherein at least one of R¹³, R¹⁴, and R¹⁵ isa photographic ballast group.
 5. A photographic element as in claim 1wherein the coupler (A) is an acetanilide or naphtholic coupler.
 6. Aphotographic element as in claim 1 wherein the coupler (A) is anaphtholic coupler represented by the formula: ##STR48## wherein; R¹⁹ ishydrogen, CH₃, methoxyphenyl, hydroxyethoxyphenyl, carboxyphenyl, --CH₂CO₂ CH₃, --CH₂ CH₂ COOH or --CH₂ OCH₂ CH₂ COOH;R²⁰ is a photographicballast or a substituent; R²¹ and R²² are selected from hydrogen,substituted or unsubstituted alkyl or substituted or unsubstituted arylor a photographic ballast; R²³ is nitro; R²⁴ and R²⁵ are selected fromhydrogen; substituted or unsubstituted alkyl or substituted orunsubstituted aryl; and INH is a heterocyclic development inhibitorgroup.
 7. A photographic element as in claim 1 wherein the coupler (A)is selected from couplers I-13 through I-16.
 8. A process of forming aphotographic image which comprises developing an exposed photographicsilver halide emulsion layer with a color developing agent in thepresence of coupler (A) as defined in claim
 1. 9. A process in claim 8wherein the coupler (A) is as defined in claim 7.